报告摘要：I review the status of Big Bang Nucleosynthesis, one of the most sensitive probes of the early Universe. The observations of primordial elements (helium and deuterium) are consistent with theory predictions. This consistency set a tight set of constraints on physics beyond Standard Model. At the same time, the observations of lithium are a factor ~ 3-4 lower than predicted. I will discuss possible resolutions of this discrepancy.